The
Indian Regional Navigation Satellite System or
IRNSS is an indigenously developed
Navigation Satellite System that is used to provide accurate real-time positioning and timing services over India and region extending to 1500 km around India. The fully deployed IRNSS system consists of 3 satellites in GEO orbit and 4 satellites in GSO orbit, approximately 36,000 km altitude above earth surface. Though the full system comprises nine satellites, including two on the ground as stand-by. The requirement of such a navigation system is driven because access to foreign government-controlled
global navigation satellite systems is not guaranteed in hostile situations, as happened to the Indian military depending on American
GPS during the
Kargil War. The IRNSS would provide two services, with the Standard Positioning Service open for civilian use, and the Restricted Service (an encrypted one) for authorised users (including the military).